Where to remove fftw links

In the General Discussion forum in my panda3d liscense questions thread

I don’t want my game-logic code to fall under the GPL, so I would like a version of Panda3D that doesn’t link to libfftw. drwr indicated that I can easily do without the library, and should modify the Panda3D source to remove the link and recompile. Does anybody know how to do that? Where are the links and how do I remove them so the code still compiles properly?

Download the Panda3D source. Read the INSTALL-MK document, which gives instructions for building your own version from source. Follow those instructions to be sure you understand them.

When you have successfully built your own Panda using the default source as provided, modify makepanda.py and remove the references to fftw. Then build it again with your modified Panda.

Alternatively, instead of using makepanda.py, you can use the ppremake system–read the INSTALL-PP document for these instructions. In this case, you can easily customize a version of Panda that uses exactly the set of third-party libraries you wish to use. However, the ppremake build system is somewhat more complex than the makepanda build system, so I recommend using the makepanda build system unless you are very comfortable with installing C++ software.